Raised floor plate



April 30, 1968 J. 5. MIKUS 3,380,217

RAI SED FLOOR PLATE Filed Jul 15, 1965. 2 Sheets-Sheet 1 INVENTOR: JUHN 5. MIKUS.

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IHIIEI United States Patent 3,380,217 RAISED FLOOR PLATE John S. Mikus, Toledo, Ohio, assignor to National Lead glompany, New York, N.Y., a corporation of New ersey Filed July 15, 1965, Ser. No. 472,269 3 Claims. (Cl. 52-630) ABSTRACT OF THE DISCLOSURE The invention discloses a stamped floor plate for raised floors comprising a relatively heavy upper plate and a reinforcing body including webs afiixed to and extending downwardly from the upper plate to a lower plate from which the webs are formed. A peripheral web is formed from the lower plate and is welded to the underside of the upper plate. The upper plate extends outwardly to receive a plastic lip which forms a recess into which a decorative finishing material for the floor is inserted.

This invention relates to a raised floor of the type that is now used extensively in rooms housing computers and similar installations in which a large number of interunit cables are required. Such cabling is frequently changed around as the installation is changed and the raised floor plates are taken up for this purpose to expose the sub-floor cable space.

Two general types of raised floors are in common use. One consists of panels supported along opposite edges on stringers, and the other is the so-called infinite access floor in which each plate is supported only at its four corners on spaced pedestals. The latter floor has several advantages, notably the improved ease with which cables can be laid in any direction without interference and without the necessity of feeding them under the supporting stringers. However, the structure of the plates is somewhat more exacting where the extent of the support is reduced from the full edge to only the corners of the plates.

The art is familiar with corner supported plates comprising die cast bodies having depending reinforcing ribs. Such plates are highly satisfactory from a structural standpoint and can be made very strong. High unit loading can be imposed with only very minor deflections so that heavy computers can be rolled from place to place without damaging the fioor. The die cast plates are costly, however, and are used primarily where the installation is expected to be reasonably permanent and where the cost of the floor is of minor importance.

The present invention is directed primarily to a less expensive floor plate made from sheet steel. The primary object of the invention is to provide a drawn or stamped underbody in which a beam reinforcement is developed in each mutually perpendicular direction so that the resulting plate is strong and capable of accepting high unit loadings of, for example, 1000 pounds on any one square inch.

The stamped underbody is welded or otherwise afiixed to a continuous fiat upper sheet that overlaps the periphery of the underbody on all four sides. Certain attempts have been made in the past to provide a built-up floor plate stamped from sheet metal. If the metal is soft enough to be drawn satisfactorily, it has been generally found that it is so soft that it will dimple or deform in use. The present invention, utilizing a continuous and fiat upper sheet, overcomes the disadvantages of known constructions because the upper sheet can be made of a very hard metal that would not be satisfactory if it had to undergo any stamping or drawing operation. Further, the upper sheet can be made as thick as is desirable since it does not undergo any forming operation. The perimeter of the upper sheet is protected by a plastic lip and the space within the protrusion of the lip above the plane of the upper sheet is filled with a floor covering material such as vinyl tile, asbestos tile, wood flooring or carpeting.

A preferred embodiment of the invention is shown in the accompanying drawings, in which:

FIGURE 1 is a fragmentary plan view of an underbody sheet in an intermediate stage of fabrication;

FIG. 2 is a fragmentary perspective view of an underbody sheet drawn to its final configuration;

FIG. 3 is a top plan view of an elevated floor with parts broken away to expose the underbody sheet; and

FIG. 4 is an enlarged section taken on line 44 of FIG. 3.

FIGURE 1 of the drawings shows a portion of a flat sheet of metal 10, usually steel, that has been blanked out to a suitable rectangular configuration and on which certain preliminary operations have been performed. Each corner of the plate has been cut out, as at 11, so that the perimeter can be bent first at right angles to the plane of the sheet and then into a parallel plane to form a fiat perimetrical rim 12 without overlapping at the corners. The flat rim is reinforced by the downwardly extending formed portion 13.

Further, the sheet shown in FIG. 1 has been pierced at spaced intervals at 14 in areas that will subsequently be drawn into spaced polygonal pockets. In the form shown the polygonal pockets are to be formed as rectangles, and each pierced hole 14 is connected by slits 15 to corner holes 16. The piercing and slitting operation results in a group of four identical triangular metal members 17, the apexes of the triangles lying in the common hole 14 and the remaining corners in the holes 16, with the base being defined by a line 18 spaced slightly outwardly from a line of tangeney between adjacent holes 16. Since the configuration and formation of each pocket is the same, only one will be described in detail.

The pierced and slitted sheet shown in FIG. 1 is next drawn to the configuration shown in FIG. 2. Each of the triangular metal members 17 is bent upwardly along line 18 into a plane perpendicular to the plane of the sheet to form respective reinforcing webs 19 which occur at right angles to each other. The inner portion 20 of each of the triangular metal bodies is bent inwardly along a line 21 to form a tab 22 lying in a plane parallel to the original plane of the underbody sheet 10 but spaced therefrom a distance equal to the height of the reinforcing web 19. It will be seen that the base of the reinforcing web 19 is co-extensive with the side of a pocket, designated 23, and that all four sides of a pocket are reinforced similarly.

Inasmuch as a sheet is formed with a series of spaced pockets 23, that portion of the underbody sheet between the pockets and lying in the original plane of the sheet is designated as a lower Web 24 in FIG. 2. The web 24 consists of a grid of continuous strips of metal effectively extending from each side of the underbody sheet to the opposite side, as shown in FIG. 3. The only portion of the entire underbody that is not connected to the top plate by a reinforcing web 19 is that portion lying between adjacent pockets and defined by the webs 24. The dimension of these webs can be made as small as is desirable, based on the unit loading and deflection characteristics that the completed plate will be called upon to exhibit in service, It is only by the subdivision of the reinforcing webs into four webs for each pocket that this extensive reinforcing is obtained.

After the sheet 10 has been drawn to the configuration shown in FIG. 2, the floor plate is completed, insofar as the metallic portions are concerned, by welding or otherwise aflixing the underbody 10 to a continuous top plate 26. Dimensionally, plate 26 is made larger than the underbody rim 12 and extends over the rim on all sides. The plate 26 is preferably welded to each of the inwardly extending tabs 20 by spot Welding, and the plate is also welded to the perimetrical rim 12 at suitable intervals. The resulting structure is functionally an integral piece and is very strong against vertical deflections. The top plate 26 may be made of a hard, thick material selected for its resistance against dimpling and deformation since it undergoes no structural change such as drawing or stamping. Thus, the material of the upper plate may be characterized as relatively hard with relation to the material of the underbody 10.

As shown in FIGS. 3 and 4, the floor is assembled by laying the plates over supporting pedestals. The pedestals comprise a cruciform head 30 having a depending tubular shank 31 received over a threaded rod 32 and held in vertical adjustment by a leveling nut 33. A suitable base 34 is attached to the lower end of the supporting rod 32 and rests on the permanent building floor.

Each arm of the cruciform head 30 is made wide enough to receive adjacent corners of two floor plates, being engaged by the rims thereof, as shown in FIG. 4.

The floor plate of the present invention is finished by attaching a plastic lip piece 40 entirely around the perimeter. The lip has a central recess 41 into which the top plate 26 is forced, and the lower portion of the lip piece extends inwardly of the plate in the space left by the rim 12 of the underbody. It is for this reason that the top plate is made larger than the underbody. A sheet of finishing material or floor covering 42 is affixed to the top surface of the upper plate and is usually selected to be about as thick as the extension of the plastic lip above the plane of the floor plate. The floor covering 42 may be vinyl tile or the like.

If desired the lower surface of the completed floor plate may be sprayed with a sound deadening material such as a foamed elastomer.

While the invention has been disclosed in conjunction with a specific form and disposition of the parts, and with a fioor plate having symmetrically disposed recesses .4 and reinforcing webs, it should be understood that the disclosure is purely illustrative, and that numerous modifications and changes may be made without departing from the scope of the appended claims.

What I claim is:

1. A plate for a raised fioor comprising, a fiat upper sheet of weldable metal, an underbody Welded to said sheet having an upper plane coincident with the underside of said upper sheet and a lower plane spaced therefrom, a plurality of reinforcing webs extending at right angles from the lower plane of said underbody to the upper plane thereof and forming a multiplicity of spaced polygonal pockets in said underbody, said webs being formed at each of the sides of each of said pockets, an inturned tab member integral with each of said reinforcing webs and adapted to be welded to the undersurface of said upper sheet, a spaced perimetrical rim formed on said underbody and welded to said upper sheet, and a continuous reinforcing web extending at right angles from said rim to the lower portion of said underbody.

2. A floor plate as defined in claim 1 in which said upper sheet extends beyond the rim of said underbody on all sides.

3. A floor plate as defined in claim 2, a plastic lip piece on the perimeter of said upper sheet and extending above the plane thereof, and a body of floor covering material afiixed to said upper sheet within the confines of said lip piece.

References Cited UNITED STATES PATENTS 3,008,551 11/1961 Cole 57-618 X 3,067,843 12/1962 Rushtoh et a1 52650 3,150,748 9/1964 Liskey 52126 X 3,157,254 11/1964 Spiselman et al 52126 X 3,279,134 10/1966 Donovan 52126 BOBBY R. GAY, Primary Examiner.

DAVID J. WILLIAMOWSKY, Examiner.

R. D. KRAUS, Assistant Examiner. 

